When a wire is connected to a circuit board from the outside, a board side connector is generally provided with the circuit board to mate with a wire side connector generally provided for the wire.
Known board side connectors include a housing, and a plurality of terminals held in the housing. One end of a terminal is inserted into a receiving passageway formed in the circuit board, and the terminal and a conductive pattern provided around the receiving passageway are soldered and electrically connected.
Known board side connectors may include a vertical type connector with which a wire side connector is mated in a direction perpendicular to a surface of a circuit board, or a horizontal type connector with which a wire side connector is mated in a direction parallel to a surface of a circuit board.
As shown in FIG. 7A, in a known wire connector 1 of a horizontal type, a terminal 2 has a substantially L shape so that a board side end 2a is perpendicular to a surface 3a of a circuit board 3, and a tip 2b engaging a female terminal of the wire side connector extends in parallel with the surface 3a of the circuit board 3 (for example, see Japanese Patent Laid-Open No. 2010-113976 and Japanese Patent Laid-Open No. 2005-327589).
However, it is difficult to ensure positional accuracy of the board side end 2a of the terminal 2 inserted into the receiving passageway formed in the circuit board 3 for the known wire connector 1 using the substantially L-shaped terminal 2.
Specifically, the substantially L-shaped terminal 2 originally has a straight shape, as shown in FIG. 7B. Initially, the terminal 2 is inserted into a receiving passageway 5 formed in a housing 4. At this time, the terminal 2 is inserted from a side of a hood portion 4a of the housing 4 which the wire side connector engages. Then, as shown in FIG. 7C, the terminal 2 is press-fit into the receiving passageway 5 in the housing 4. Then, as shown in FIG. 7A, the terminal 2 is bent 90 degrees and deformed into the substantially L shape.
During assembly, when the straight terminal 2 is first inserted into the receiving passageway 5, a slight displacement of an insertion angle from the hood portion 4a of the housing 4 causes a large displacement of the board side end 2a of the terminal 2 after bending. To prevent the displacement, accuracy in the molding of the housing 4 and the terminal 2, or the like needs to be increased, but increasing accuracy as intended is difficult in view of cost.
The terminal 2 is inserted into the housing 4 and then bent to cause springback, and this causes displacement of the board side end 2a of the terminal 2 in a Z direction in FIG. 7A. The terminal 2 is naturally bent in view of an amount of deformation by the springback, but still the position of the board side end 2a of the terminal 2 varies in the Z direction.
If the position of the board side end 2a of the terminal 2 varies, board side ends 2a of all terminals 2 cannot be smoothly inserted into receiving passageways formed in the circuit board 3 in mounting the wire connector 1 on the circuit board 3. Thus, conventionally, a terminal alignment plate 6 having a receiving passageway through which the board side end 2a of each terminal 2 is inserted is provided on the housing 4 to correct variations in position of the board side end 2a of the terminal 2.
However, if the terminal alignment plate 6 is provided, the number of components of the wire connector 1 is increased, which requires more work during assembly and increases cost.
With the terminal alignment plate 6, when the circuit board 3 and the board side end 2a of the terminal 2 are soldered by reflow, the terminal alignment plate 6 blocks hot air for melting solder paste previously applied onto the wiring pattern of the circuit board 3. Then, soldering cannot be reliably performed in some cases, which increases the rate of occurrence of defective products.
Also, with the terminal alignment plate 6, when spray antiseptic is applied after the wire connector 1 is mounted on the circuit board 3, the terminal alignment plate 6 prevents the antiseptic from being applied onto a back side region of the terminal alignment plate 6.
Further, with the terminal alignment plate 6, a footprint of the wire connector 1 on the circuit board 3 is increased by a area of the terminal alignment plate 6, which prevents effective use of space on the circuit board 3.
For such problems, a technique described in Japanese Patent Laid-Open No. 2009-163991 proposes that a terminal is partially held in a housing to increase positional accuracy along a board side end of the terminal.
However, in this technique, a first horizontal portion extending in an inserting direction of the terminal into the housing, and also a first connecting portion extending in a direction perpendicular to the first horizontal portion are held in the housing. Thus, a groove must be formed in the housing to hold the first connecting portion, which complicates a structure of the housing, and requires work in assembling the terminal to the housing.